1. Field of the Invention
Apparatuses and methods consistent with exemplary embodiments of the present general inventive concept relate to an image generating apparatus and method, and more particularly, to an image generating apparatus and method, capable of reducing noise when a still image is generated from a live view image.
2. Description of the Related Art
Most of digital cameras or smart phones developed in recent years provide an electrical view finder configured to let a user check a subject and a captured image with a naked eye. In capturing an image, the electrical view finder processes image information detected in an image sensor and displays a live view image. When the user operates a shutter, electronic apparatuses generate a still image corresponding to the live view image at a point of time when the shutter is operated.
Some electronic apparatuses provide a continuous shooting function configured to continuously capture a subject in preset time units and acquire pieces of still images. Since large amounts of data are required to perform the continuous shooting function, system performance of above a certain level is required to display a live view image while a series of still images output by the continuous shooting are processed.
As one method of solving the problem, technology to generate a still image by generating a live view image using only a portion of an image sensor, and combining the portion of the image sensor and the remainder of the image sensor in continuous shooting is suggested. FIG. 1 illustrates the above-described method.
That is, FIG. 1 is a schematic diagram illustrating technology to divide an image sensor to perform continuous shooting.
As illustrated in FIG. 1, the image sensor is configured of a plurality of pixels (total pixels 10). The total pixels 10 are divided into a first pixel group 11 configured to generate a live view image and a second pixel group 12 configured to generate a still image. The second pixel group 12 is configured of remaining pixels among total pixels 10 other than pixels constituting the first pixel group 11. For example, as illustrated in FIG. 1, the first pixel group 11 may include a red (R) pixel having coordinates (0,0), a green-red (Gr) pixel having coordinates (0,3), a green-blue (Gb) pixel having coordinates (3,0), and a blue (B) pixel having coordinates (3,3), and the second pixel group 12 may include the remaining pixels other than the pixels included in the first pixel group 11.
Live view image display is performed by processing data of the first pixel group 11. When there is a continuous shooting command, a still image having full resolution is generated by combining the first pixel group 11 and the second pixel group 12. When shutter speed, which may also be referred to as a frame rate of the still image, is smaller than a frame rate of a live view image, the above-described process is performed by adding an additional frame of the live view image, corresponding to the shutter speed. For example, when the shutter speed is ½ of the frame rate of the live view image, the second pixel group 12 of two pieces of continuous frames of the live view image is used to generate the still image.
The technology to independently generate the still image using only portions of pixel values of an image sensor while continuously providing the live view image promotes convenience of a user.
However, as described above, when the shutter speed is smaller than the frame rate of the live view image, since exposure data of the image sensor has to be read out plural times to generate one piece of still image, noise generated in the read-out process is increased. Therefore, there is a need for a method to reduce the read-out noise in the technology.